X0303 4 2008-08-11 0001301081 Pharmasset Inc VRUS 0001284621 OTTO MICHAEL 303A COLLEGE ROAD EAST PRINCETON NJ 08540 0 1 0 0 Chief Scientific Officer Common Stock 2008-08-11 4 M 0 5835 3.00 A 25335 D Common Stock 2008-08-11 4 S 0 1500 21.06 D 23835 D Common Stock 2008-08-11 4 S 0 156 21.07 D 23679 D Common Stock 2008-08-11 4 S 0 100 21.11 D 23579 D Common Stock 2008-08-11 4 S 0 400 21.32 D 23179 D Common Stock 2008-08-11 4 S 0 300 21.38 D 22879 D Common Stock 2008-08-11 4 S 0 100 21.40 D 22779 D Common Stock 2008-08-11 4 S 0 100 21.41 D 22679 D Common Stock 2008-08-11 4 S 0 800 21.43 D 21879 D Common Stock 2008-08-11 4 S 0 100 21.47 D 21779 D Common Stock 2008-08-11 4 S 0 300 21.49 D 21479 D Common Stock 2008-08-11 4 S 0 200 21.50 D 21279 D Common Stock 2008-08-11 4 S 0 300 21.56 D 20979 D Common Stock 2008-08-11 4 S 0 300 21.64 D 20679 D Common Stock 2008-08-11 4 S 0 157 21.66 D 20522 D Common Stock 2008-08-11 4 S 0 100 21.70 D 20422 D Common Stock 2008-08-11 4 S 0 100 21.77 D 20322 D Common Stock 2008-08-11 4 S 0 100 21.78 D 20222 D Common Stock 2008-08-11 4 S 0 700 21.80 D 19522 D Common Stock 2008-08-11 4 S 0 22 21.82 D 19500 D Stock Option (Right to Buy) 3.00 2008-08-11 4 M 0 5835 0 D 2014-08-09 Common Stock 5835 0 D The option was granted on August 10, 2004 and became vested 25% on August 10, 2005 and 6.25% each quarter thereafter. All transactions described on this Form 4 are the result of standing instructions set forth in a Rule 10b5-1 plan previously established by Dr. Otto. Bryce A. Roberts, Attorney in Fact for Michael J. Otto 2008-08-13